mulleri infestation causes increased heartbeat and scaphognathite
fluttering rates, and severely weakens individuals with heavy infestations (Gannon & Wheatly 1994, Wu & Liu 1995).
3) and may be linked to episodic reversal or cessation of scaphognathite
(gill-pump) beating common in marine crustaceans (Taylor, 1982).
For example, an increase in scaphognathite
beating rates, which increases ventilation at the gills and maintains hemolymph [Po.
Maxilla and first maxilliped with dense covering of setae-like structure formed by bacterial colony on ventral surfaces of scaphognathite
and caridean lobe, respectively (Fig.
1F) Palp with 2, 1, 1, 2 setae; coxal endite with 6 distal setae; basal endite with 8 distal setae; broad scaphognathite
with narrow posterior lobes having long naked setae.
Heart rate and scaphognathite
beat frequency remain depressed after oxygen uptake returns to pretreatment levels (McGaw, 2006), which suggests that the observed short-term decrease in oxygen uptake is attributable to changes in activity level (McMahon et al.
The morphological characters of the first postlarva are 43 scaphognathite
setae on the maxilla, three scaphocerite spines on the outer margin of antenna, and sternal plate spines: 2,2,0,1,1.
Certain elements of cardiovascular function specifically relating to the gill circulation were monitored; we quantified heart and scaphognathite
function, and measured the hemolymph hydrostatic pressure change across the gill circulation in both saline- and Vibrio-injected crabs.
In decapods, maxilla 2 is responsible for ventilating the gills via the scaphognathite
(gill bailer), and it therefore moves more-or-less constantly and in a stereotypical way (Garm and H0eg, 2001).
For each animal, the salinity in the recording chamber was gradually lowered from a starting value of 32 ppt to less than 20 ppt, at a rate of 1-2 ppt/min, while heart and scaphognathite
rates were continuously recorded.
Since it is difficult to video-record the mouth parts with high magnification during social interactions, we are currently testing other methods of monitoring scaphognathite
beating frequencies during encounters to verify this hypothesis.
Labrum (Lb), mandibular incisor (Inc) and molar process (Mp), mandibular palp (Mdp), maxilla 1 coxa (Mxl cox), maxilla 1 basis (Mxl bas), maxilla 1 endopod (Mx1 endo), maxilla 2 coxa (Mx2 cox), maxilla 2 basis (Mx2 bas), maxilla 2 endopod (Mx2 endo), scaphognathite
(Scapho), maxilliped 1 coxa (Mxpl cox), maxilliped 1 basis (Mxpl bas), maxilliped 1 endopod (Mxpl endo), maxilliped 1 exopod (Mxpl exo), maxilliped 1 epipod (Mxpl epi), maxilliped 2 endopod (Mxp2 endo), maxilliped 2 exopod (Mxp2 exo), maxilliped 3 endopod (Mxp3 endo), maxilliped 3 exopod (Mxp3 exo).